A flood discharge tunnel inlet structure and method suitable for rivers with high sediment and high rock mass

Abstract

The present invention provides a spillway inlet structure and method suitable for rivers with high sediment content and large boulders, comprising a bottom plate, a left pier, a right pier, a middle pier, a left connecting beam, and a right connecting beam; the middle pier is disposed between the left pier and the right pier, the left connecting beam is disposed between the left top of the middle pier and the top of the left pier, so that the middle pier and the left pier are connected by the left connecting beam; the right connecting beam is disposed between the right top of the middle pier and the top of the right pier, so that the middle pier and the right pier are connected by the right connecting beam. The present invention is suitable for the design of spillway inlet structures for rivers with high sediment content and large boulders, and can effectively address sedimentation problems, prevent sediment and boulders from entering the spillway and causing structural instability in the spillway, thereby ensuring the normal flood discharge function of the spillway while ensuring structural stability and safety.

Description

Technical Field

[0001] The invention belongs to the technical field of design of spillway inlet structures of water conservancy and hydropower projects, and particularly relates to a spillway inlet structure and method suitable for rivers with a lot of sediment and rocks. Background Art

[0002] Currently, the most commonly used spillway tunnels in hydropower projects are small-opening gate spillways, suitable for flood and sediment discharge in rivers with low sediment accumulation and the absence of large boulders. However, when unfavorable conditions such as heavy sediment accumulation and large boulders are present in the river, the spillway tunnel's limited sediment discharge capacity and structural stability can easily lead to problems such as siltation at the spillway inlet, damage to the spillway body by boulders, affecting the stability of the lining structure, and damage to the gates by boulders. Therefore, conventional spillway structures are no longer able to meet the flood and sediment discharge needs of rivers with high sediment and boulders. Summary of the Invention

[0003] In view of the defects of the existing technology, the present invention provides a flood discharge tunnel inlet structure and method suitable for rivers with high sediment and large rocks, which can effectively solve the above problems.

[0004] The technical solution adopted in the present invention is as follows:

[0005] The present invention provides a flood discharge tunnel inlet structure suitable for a river with a lot of sediment and rocks, comprising a bottom plate (1), a left pier (2), a right pier (3), a middle pier (4), a left connecting beam (5) and a right connecting beam (6);

[0006] The left pier (2) and the right pier (3) are symmetrically arranged on the left and right sides of the bottom plate (1), so that a flood discharge channel is formed between the left pier (2) and the right pier (3); the middle pier (4) is arranged between the left pier (2) and the right pier (3), and the left connecting beam (5) is arranged between the left top of the middle pier (4) and the top of the left pier (2), so that the middle pier (4) and the left pier (2) are connected through the left connecting beam (5); the right connecting beam (6) is arranged between the right top of the middle pier (4) and the top of the right pier (3), so that the middle pier (4) and the right pier (3) are connected through the right connecting beam (6).

[0007] Preferably, the flow-through surfaces of the left pier (2) and the right pier (3) are streamlined.

[0008] Preferably, the flow surfaces of the left pier (2) and the right pier (3) are elliptical curves, and the elliptical curve equation is: 2 / 14.0 2 +y 2 / 2.7 2=1; wherein x and y are coordinates of the elliptic curve, so that the width of the flood discharge channel formed between the left pier (2) and the right pier (3) is the largest at the entrance position along the flood discharge flow direction and then gradually decreases.

[0009] Preferably, the left and right side surfaces of the middle pier (4) are streamlined.

[0010] Preferably, the cross section of the middle pier (4) is elliptical, the major axis of the ellipse is arranged along the central axis between the left pier (2) and the right pier (3), and the curve equation of the ellipse is x 2 / 3.0 2 +y 2 / 1.0 2 =1; where x and y are the coordinates of the elliptic curve.

[0011] Preferably, the length of the middle pier (4) along the flood discharge flow direction is shorter than the lengths of the left pier (2) and the right pier (3).

[0012] Preferably, a first gate slot (2-1) is vertically provided on the flow surface of the left pier (2), and the left end of the left connecting beam (5) is located at the top of the first gate slot (2-1); a second gate slot (4-1) is vertically provided on the left side surface of the middle pier (4), and the right end of the left connecting beam (5) is located at the top of the second gate slot (4-1);

[0013] A third gate slot (3-1) is vertically arranged on the flow surface of the right pier (3), and the right end of the right connecting beam (6) is located at the top of the third gate slot (3-1); a fourth gate slot (4-2) is vertically arranged on the right side surface of the middle pier (4), and the left end of the right connecting beam (6) is located at the top of the fourth gate slot (4-2).

[0014] Preferably, a plurality of stoplogs (7) are arranged vertically in blocks inside the first door slot (2-1), the second door slot (4-1), the third door slot (3-1) and the fourth door slot (4-2).

[0015] The present invention also provides a method for constructing a flood discharge tunnel inlet structure suitable for a river with a lot of sediment and rocks, comprising the following steps:

[0016] Step 1: construct a flood discharge tunnel inlet structure suitable for rivers with high sediment and high rock mass;

[0017] Step 2: When the river with a lot of sediment and rocks reaches the entrance position of the flood discharge tunnel inlet structure, the river with a lot of sediment and rocks hits the middle pier (4). Through the diversion effect of the middle pier (4), the river with a lot of sediment and rocks is divided into two streams, which flow through the left flood discharge branch between the left pier (2) and the middle pier (4) and the right flood discharge branch between the right pier (3) and the middle pier (4). After passing through the middle pier (4), the rivers on both sides converge and continue to flow;

[0018] During this process, due to the diversion effect of the middle pier (4) and the shape characteristics of the left and right flood discharge branches, the water flow velocity can be increased, thereby carrying sediment and flowing, avoiding sediment accumulation, and improving the sediment discharge capacity; due to the structural effect of the left connecting beam (5) and the right connecting beam (6), as well as the arrangement of the gate slot and the stop beam (7), the structural stability of the flood discharge tunnel inlet structure is increased.

[0019] Preferably, step 1 is specifically:

[0020] S1.1, before the structure is constructed, the foundation surface and slope excavation shall be carried out according to the structural requirements;

[0021] S1.2, after the excavation construction is completed, the bottom plate (1) is constructed so that the bottom plate (1) is set on the fresh bedrock surface, and then the left pier (2), the right pier (3), and the middle pier (4) are constructed. During the construction of the left pier (2), the right pier (3), and the middle pier (4), a door slot is reserved according to the required size;

[0022] S1.3, when the left pier (2), right pier (3), and middle pier (4) are constructed to the connection beam elevation, they shall be cast in situ simultaneously with the connection beam to ensure that the left pier (2), middle pier (4) and left connection beam (5) are effectively connected, and that the right pier (3), middle pier (4) and right connection beam (6) are effectively connected to form the flood discharge tunnel entrance structure;

[0023] S1.4, the completed prefabricated stoplog (7) is placed into the door slots reserved on the sides of the left pier (2), the right pier (3) and the middle pier (4) during the initial low water level period or the static water level period in the reservoir.

[0024] The invention provides a flood discharge tunnel inlet structure and method suitable for rivers with a lot of sediment and rocks, which has the following advantages:

[0025] The present invention provides a spillway inlet structure suitable for rivers with high sediment content and high rock mass. The structure is suitable for the spillway inlet structure design of rivers with high sediment content and high rock mass. The structure can effectively deal with sediment accumulation problems, prevent sediment and rock masses from entering the spillway and causing structural instability of the spillway, thereby ensuring the normal flood discharge function of the spillway and ensuring structural stability and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A three-dimensional structural diagram of a flood discharge tunnel inlet structure suitable for rivers with a lot of sediment and rocks provided by the present invention at one angle;

[0027] Figure 2 A three-dimensional structural diagram of a flood discharge tunnel inlet structure suitable for rivers with a lot of sediment and rocks provided by the present invention, viewed from another angle;

[0028] Figure 3 A top view of a flood discharge tunnel inlet structure suitable for rivers with a lot of sediment and rocks provided by the present invention;

[0029] Figure 4 for Figure 3 Section view along AA. DETAILED DESCRIPTION

[0030] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] In the description of this application, it should be understood that the terms "up", "down", "front", "back", "left", "right", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on this application.

[0032] The present invention provides a spillway inlet structure suitable for rivers with high sediment content and large rocks. The structure is suitable for the spillway inlet structure design of rivers with large sediment content and many large rocks. The structure can effectively deal with sediment accumulation problems and prevent sediment and rocks from entering the spillway and causing structural instability of the spillway.

[0033] See also Figures 1 to 4 The present invention provides a flood discharge tunnel inlet structure suitable for a river with a lot of sediment and rocks, comprising a bottom plate 1, a left pier 2, a right pier 3, a middle pier 4, a left connecting beam 5 and a right connecting beam 6;

[0034] The bottom plate 1 is arranged on the bedrock surface of the riverbed. The left pier 2 and the right pier 3 are symmetrically arranged on the left and right sides of the bottom plate 1, so that a flood discharge channel is formed between the left pier 2 and the right pier 3; the middle pier 4 is arranged between the left pier 2 and the right pier 3. Therefore, the bottoms of the left pier 2, the right pier 3 and the middle pier 4 are all connected and fixed to the bottom plate 1 to ensure the overall stability of the structure.

[0035] A left connecting beam 5 is provided between the top left side of the middle pier 4 and the top of the left pier 2, connecting the middle pier 4 and the left pier 2 via the left connecting beam 5. A right connecting beam 6 is provided between the top right side of the middle pier 4 and the top of the right pier 3, connecting the middle pier 4 and the right pier 3 via the right connecting beam 6. The provision of the left connecting beam 5 achieves a stable connection between the middle pier 4 and the left pier 2, and the provision of the right connecting beam 6 achieves a stable connection between the middle pier 4 and the right connecting beam 6. Thus, the connecting beams effectively connect the side piers and the middle pier, forming a structural whole.

[0036] The flow surfaces of the left pier 2 and the right pier 3 are streamlined. Specifically, the flow surfaces of the left pier 2 and the right pier 3 are elliptical curves, and the elliptical curve equation is: 2 / 14.0 2 +y 2 / 2.7 2 =1; where x and y are the coordinates of the elliptic curve, so that the width of the flood discharge channel formed between the left pier 2 and the right pier 3 is the largest at the entrance along the flood discharge direction and then gradually decreases.

[0037] The length of the middle pier 4 along the flood discharge direction is shorter than the length of the left pier 2 and the right pier 3. The left and right sides of the middle pier 4 are streamlined. Specifically, the cross section of the middle pier 4 is an ellipse, with the major axis of the ellipse arranged along the central axis between the left pier 2 and the right pier 3. The curve equation of the ellipse is x 2 / 3.0 2 +y 2 / 1.0 2 =1; where x and y are the coordinates of the elliptic curve.

[0038] In the present invention, in order to enhance structural stability, a first gate groove 2-1 is vertically provided on the flow surface of the left pier 2, and the left end of the left connecting beam 5 is located at the top of the first gate groove 2-1; a second gate groove 4-1 is vertically provided on the left side of the middle pier 4, and the right end of the left connecting beam 5 is located at the top of the second gate groove 4-1;

[0039] A third gate slot 3-1 is vertically defined on the flow surface of right pier 3, with the right end of right connecting beam 6 positioned at the top of third gate slot 3-1. A fourth gate slot 4-2 is vertically defined on the right side of center pier 4, with the left end of right connecting beam 6 positioned at the top of fourth gate slot 4-2. During actual construction, gate slots are reserved at the corresponding locations of left pier 2, center pier 4, and right pier 3. These slots are reserved according to the required dimensions during construction of these three piers.

[0040] The arrangement center lines of the first door groove 2-1, the second door groove 4-1, the third door groove 3-1 and the fourth door groove 4-2 are consistent.

[0041] Multiple stop beams 7 are arranged vertically in blocks inside the first gate slot 2-1, the second gate slot 4-1, the third gate slot 3-1, and the fourth gate slot 4-2. The length, width, height, and total height of the stop beams 7 can be determined based on the inlet width, silt height, structural stress, construction technology, and other characteristics. The stop beams 7 should be completed before the flow passes. The purpose of installing the stop beams 7 is: because the elevation of the spillway floor is too low and the silt height is high, the stop beams 7 can be used to block the silt outside the water inlet that reaches the height range of the stop beams 7. Therefore, the spillway inlet structure can not only flush away silt deposits, but also have a certain silt deposit capacity, thereby reducing the design requirements for the spillway's sediment discharge capacity. At the same time, under the premise of meeting the flow capacity, the design cross-section of the spillway chamber can be reduced, improving the stability of the spillway chamber. The structure has good integrity and effectively combines sand and rock retaining with flood discharge. It can be used for the construction of flood discharge tunnel inlet structures under river channel conditions with high sediment content and high rock mass, and can effectively deal with the siltation problem and tunnel body stability problem at the flood discharge tunnel inlet under river channel conditions with high sediment content and high rock mass.

[0042] The present invention also provides a method for constructing a flood discharge tunnel inlet structure suitable for a river with a lot of sediment and rocks, comprising the following steps:

[0043] Step 1: construct a flood discharge tunnel inlet structure suitable for rivers with high sediment and high rock mass;

[0044] Step 1 is as follows:

[0045] S1.1, before the structure is constructed, the foundation surface and slope excavation shall be carried out according to the structural requirements;

[0046] S1.2. After the excavation is completed, the base plate 1 is constructed and placed on the fresh bedrock surface. The left pier 2, right pier 3, and middle pier 4 are then constructed. During the construction of the left pier 2, right pier 3, and middle pier 4, a door slot is reserved according to the required size.

[0047] S1.3. When the left pier 2, right pier 3, and middle pier 4 are constructed to the connection beam elevation, they shall be cast in situ simultaneously with the connection beam to ensure effective connection between the left pier 2, middle pier 4, and left connection beam 5, and between the right pier 3, middle pier 4, and right connection beam 6, forming the flood discharge tunnel entrance structure.

[0048] S1.4, place the completed prefabricated stoplog 7 into the gate grooves reserved on the sides of the left pier 2, the right pier 3 and the middle pier 4 during the initial low water level period or the static water level period in the reservoir.

[0049] Step 2: When the silt-laden and rock-laden river reaches the entrance of the spillway inlet structure, it impacts the middle pier 4. The middle pier 4 splits the silt-laden and rock-laden river into two streams, which flow through the left spillway branch between the left pier 2 and the middle pier 4 and the right spillway branch between the right pier 3 and the middle pier 4. After passing the middle pier 4, the two streams converge and continue to flow.

[0050] During this process, due to the diversion effect of the middle pier 4 and the shape characteristics of the left and right flood discharge branches, the water flow velocity can be increased, thereby carrying sediment to avoid sediment accumulation and improving the sediment discharge capacity; due to the structural function of the left connecting beam 5 and the right connecting beam 6, as well as the arrangement of the gate slot and the stop beam 7, the structural stability of the flood discharge tunnel entrance structure is increased.

[0051] The following is a further explanation of a conventional hydropower station project using the technical solution of the present invention with reference to the accompanying drawings as an example:

[0052] The width of the inlet channel of a conventional hydropower station's spillway tunnel ranges from 15.5m to 17.5m. Geological and hydrological data indicate that the channel is densely packed with sediment and rocks, posing challenges to both the sediment removal and structural stability design of the spillway tunnel.

[0053] Therefore, the structure of the present invention is set in the process of designing the entrance structure of the flood discharge tunnel: according to the test results, the elevation of the sand retaining block stone is set to be no less than 378m (height 4m), that is, the total height of the stacking beam is set to 4m, and 10 stacking beams are set in a single hole. The length of a single stacking beam is 6.25m, the width is 0.6m, and the height is 0.4m. The stacking beams are stacked separately in the gate slot. Gate slots are set on the sides of the side piers and the middle pier on both sides. The gate slot width is 0.65m to ensure that the stacking beam can be placed in the gate slot. The total height of the gate slot is 11.20m. Side piers are set along both sides of the inlet diversion channel. The outer side of the side pier spreads outward by 4.09° and has a thickness of 0.8m to 2.5m. The flow surface adopts an elliptical curve, and the curve equation is x 2 / 14.0 2 +y 2 / 2.7 2 = 1. Due to the large span, a 2.0m thick reinforced concrete pier is set. The side of the pier adopts an elliptical curve. The curve equation is x 2 / 3.0 2 +y 2 / 1.0 2 = 1. Set a 1.2m thick base plate with a width of 15.5m to 17.5m and a length of 14m to connect the middle pier and the side piers. Set a connecting beam about 6m long along the upstream and downstream sides of the top of the gate slot to connect the side pier and the middle pier. The connecting beam is 0.4m wide and 0.8m high.

[0054] It has been proven that this structural system effectively solves problems such as sedimentation at the spillway inlet and structural stability of the spillway under conditions of rivers with high sediment content and high rock mass, thus ensuring the stability and safety of the spillway structure.

[0055] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A flood discharge tunnel inlet structure suitable for rivers with a lot of sediment and rocks, characterized by: It includes a bottom plate (1), a left pier (2), a right pier (3), a middle pier (4), a left connecting beam (5) and a right connecting beam (6); The left pier (2) and the right pier (3) are symmetrically arranged on the left and right sides of the bottom plate (1), so that a flood discharge channel is formed between the left pier (2) and the right pier (3); the middle pier (4) is arranged between the left pier (2) and the right pier (3), and the left connecting beam (5) is arranged between the left top of the middle pier (4) and the top of the left pier (2), so that the middle pier (4) and the left pier (2) are connected through the left connecting beam (5); the right connecting beam (6) is arranged between the right top of the middle pier (4) and the top of the right pier (3), so that the middle pier (4) and the right pier (3) are connected through the right connecting beam (6); The flow surfaces of the left pier (2) and the right pier (3) are elliptical curves, and the equation of the elliptical curve is: 2 / 14.0 2 +y 2 / 2.7 2 =1; wherein x and y are coordinates of the elliptical curve, so that the width of the flood discharge channel formed between the left pier (2) and the right pier (3) is the largest at the entrance along the flood discharge flow direction and then gradually decreases; The cross section of the middle pier (4) is an ellipse, the major axis of the ellipse is arranged along the central axis between the left pier (2) and the right pier (3), and the curve equation of the ellipse is x 2 / 3.0 2 +y 2 / 1.0 2 =1; where x and y are the coordinates of the elliptic curve; A first gate slot (2-1) is vertically provided on the flow-through surface of the left pier (2), and the left end of the left connecting beam (5) is located at the top of the first gate slot (2-1); a second gate slot (4-1) is vertically provided on the left side surface of the middle pier (4), and the right end of the left connecting beam (5) is located at the top of the second gate slot (4-1); A third gate slot (3-1) is vertically provided on the flow surface of the right pier (3), and the right end of the right connecting beam (6) is located at the top of the third gate slot (3-1); a fourth gate slot (4-2) is vertically provided on the right side surface of the middle pier (4), and the left end of the right connecting beam (6) is located at the top of the fourth gate slot (4-2); The length of the middle pier (4) along the flood discharge direction is shorter than the lengths of the left pier (2) and the right pier (3); A plurality of stoplogs (7) are arranged vertically in blocks inside the first door slot (2-1), the second door slot (4-1), the third door slot (3-1) and the fourth door slot (4-2); The length, width, height and total height of the stoplog (7) can be determined according to the inlet width, silt height, structural stress and construction process characteristics. The stoplog (7) should be completed before the flow. The purpose of setting the stoplog (7) is as follows: since the elevation of the bottom plate of the spillway is too low and the silt height is high, the stoplog (7) can be set to block the silt outside the water inlet within the height range of the stoplog (7). Therefore, the inlet structure of the spillway can not only flush away the silt accumulation, but also have a certain silt accumulation capacity, thereby reducing the design requirements for the silt discharge capacity of the spillway; at the same time, under the premise of meeting the flow capacity, the design section of the spillway chamber can be reduced, and the stability of the spillway chamber can be improved. The method for constructing a flood discharge tunnel inlet structure suitable for a river with a lot of sediment and rocks comprises the following steps: Step 1: construct a flood discharge tunnel inlet structure suitable for rivers with high sediment and high rock mass; Step 2: When the river with a lot of sediment and rocks reaches the entrance position of the flood discharge tunnel inlet structure, the river with a lot of sediment and rocks hits the middle pier (4). Through the diversion effect of the middle pier (4), the river with a lot of sediment and rocks is divided into two streams, which flow through the left flood discharge branch between the left pier (2) and the middle pier (4) and the right flood discharge branch between the right pier (3) and the middle pier (4). After passing through the middle pier (4), the rivers on both sides converge and continue to flow; During this process, due to the diversion effect of the middle pier (4) and the shape characteristics of the left and right flood discharge branches, the water flow velocity can be increased, thereby carrying sediment and preventing sediment accumulation, thereby improving the sediment discharge capacity; due to the structural effect of the left connecting beam (5) and the right connecting beam (6), as well as the arrangement of the gate slot and the stoplog beam (7), the structural stability of the flood discharge tunnel entrance structure is increased; Among them, step 1 is specifically as follows: S1.1, before the structure is constructed, the foundation surface and slope excavation shall be carried out according to the structural requirements; S1.2, after the excavation construction is completed, the bottom plate (1) is constructed so that the bottom plate (1) is set on the fresh bedrock surface, and then the left pier (2), the right pier (3), and the middle pier (4) are constructed. During the construction of the left pier (2), the right pier (3), and the middle pier (4), a door slot is reserved according to the required size; S1.3, when the left pier (2), right pier (3), and middle pier (4) are constructed to the connection beam elevation, they shall be cast in situ simultaneously with the connection beam to ensure that the left pier (2), middle pier (4) and left connection beam (5) are effectively connected, and that the right pier (3), middle pier (4) and right connection beam (6) are effectively connected to form the flood discharge tunnel entrance structure; S1.4, the completed prefabricated stoplog (7) is placed into the door slots reserved on the sides of the left pier (2), the right pier (3) and the middle pier (4) during the initial low water level period or the static water level period in the reservoir.

2. The flood discharge tunnel inlet structure suitable for rivers with a lot of sediment and rocks according to claim 1, characterized in that: The flow-through surfaces of the left pier (2) and the right pier (3) are streamlined.

3. The flood discharge tunnel inlet structure suitable for rivers with a lot of sediment and rocks according to claim 1, characterized in that: The left and right side surfaces of the middle pier (4) are streamlined.

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